US4480979A - Stretch forming hollow articles - Google Patents

Stretch forming hollow articles Download PDF

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Publication number
US4480979A
US4480979A US06/298,917 US29891781A US4480979A US 4480979 A US4480979 A US 4480979A US 29891781 A US29891781 A US 29891781A US 4480979 A US4480979 A US 4480979A
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United States
Prior art keywords
sheet
tool
stretch
blades
stretching
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Expired - Lifetime
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US06/298,917
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English (en)
Inventor
Donald G. Keith
Anthony E. Flecknoe-Brown
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AARC Management Pty Ltd
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AARC Management Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US06/040,312 external-priority patent/US4288401A/en
Application filed by AARC Management Pty Ltd filed Critical AARC Management Pty Ltd
Priority to US06/298,917 priority Critical patent/US4480979A/en
Priority to GR67389A priority patent/GR76068B/el
Priority to BE0/207379A priority patent/BE892233A/fr
Priority to PCT/AU1982/000016 priority patent/WO1982002850A1/fr
Priority to EP82900606A priority patent/EP0072832A1/fr
Priority to ZA821179A priority patent/ZA821179B/xx
Priority to AU81441/82A priority patent/AU8144182A/en
Priority to IT8219802A priority patent/IT1235456B/it
Priority to PT74483A priority patent/PT74483B/pt
Priority to IL65231A priority patent/IL65231A0/xx
Priority to KR1019820001168A priority patent/KR830008818A/ko
Assigned to A.A.R.C. (MANAGEMENT) PTY. LIMITED reassignment A.A.R.C. (MANAGEMENT) PTY. LIMITED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: FLECKNOE-BROWN, ANTHONY E., KEITH, DONALD G.
Publication of US4480979A publication Critical patent/US4480979A/en
Application granted granted Critical
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/04—Combined thermoforming and prestretching, e.g. biaxial stretching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/08—Deep drawing or matched-mould forming, i.e. using mechanical means only
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/26—Component parts, details or accessories; Auxiliary operations
    • B29C51/30—Moulds
    • B29C51/34—Moulds for undercut articles

Definitions

  • This invention relates to a method and apparatus for stretch-forming hollow articles (e.g. cups) from a heat-softened sheet of thermoplastics material and to stretch-formed plastics hollow articles.
  • hollow articles e.g. cups
  • 460 849 discloses a method of stretch-forming a heat-softened sheet of melt-spinnable plastics material held against substantial non-stretching movements in which the sheet is stretched initially by a movement of a cold tip of a needle or knife edge relative to the sheet which causes the tip to press against one face of the sheet and stretch or "cuspate" part of the sheet into a cuspidate parison which it is postulated can then be dilated by blowing it into a cavity mould by pneumatic pressure.
  • the cold tip chills and therefore strengthens the localised blob of heat-softened plastics material at the cusp against which the tip presses and so the chilled blob prevents puncture of the sheet by the tip and enables unchilled portions of the sheet to stretch in response to pressure exerted on the blob by the tip.
  • British patent specification No. 1 378 945 discloses an alternative method of stretch-forming a heat-softened sheet of a polyolefin.
  • a polyolefin melt-spinnable plastics materials.
  • the sheet is held against substantial non-stretching movement and is stretched initially by a movement of a stretching tool relative to the sheet which causes the leading end of the tool to press against one face of the sheet and to stretch part of the sheet into a parison which is then dilated by blowing into a cavity mould by pneumatic pressure to form a cup.
  • the special stretching tool comprises a leading end and a body formed with integral longitudinally extending recesses. Therefore the only portions of the tool to contact the sheet during stretching are its leading end and its lobial tips. This leaves large portions of the sheet free from contact with the tool and free to stretch unhindered by frictional forces and premature cooling.
  • the tips are integral with the body of the tool and cannot be separated from one another and so after an initial stretching by the tool, GB No. 1 378 945 must rely on a blowing process for dilation and hence a cavity mould and means for supplying pneumatic pressure are needed. Also, despite the use of lobial tips, large areas of the sheet still contact the stretching tool.
  • Australian patent specification No. 220 445 discloses a method and apparatus for producing a hollow open-topped container by pressing an expansible plunger against a confined molten sheet of polyethylene, to the desired depth of draw, then expanding the plunger laterally, allowing the polythene to set, and finally collapsing and retracting the plunger.
  • the polythene may be blown pneumatically against the wall of a female mould while still hot after shaping by the plunger. It is found that this method does not produce containers of sufficiently uniform wall thickness to enable any saving of material to be realised.
  • this invention provides a method of stretch-forming a hollow article (e.g. a cup) from a sheet of thermoplastic material at a temperature higher than 75 degrees celsius below the melting point and held against substantial non-stretching movement wherein the sheet is stretched initially by primary movement relative to the sheet of a stretching tool which movement presses the tool against one face of the sheet; characterised in that the tool comprises tips which press against the sheet during stretching and which are at a temperature lower than 20 degrees celsius below the temperature of the sheet and in tha the initially stretched sheet is simultaneously, with the continued primary movement of the stretching tool, dilated in a direction transverse to the direction of the primary movement of the stretching tool.
  • the stretching of the sheet into a cuspidate parison by an initial movement of a stretching tool is called "cuspation" by Au No. 460 849.
  • the invention also provides apparatus for stretch-forming a heat-softened sheet of thermoplastic material, the apparatus comprising means to hold the sheet against substantial non-stretching movement, a stretching tool, and means to cause a primary movement of the stretching tool relative to the sheet so as to cause the tool to press against the sheet and to stretch the sheet characterised in that the stretching tool comprises tips for pressing against the sheet to cause it to stretch and means to dilate the sheet simultaneously with the continued primary movement of the stretching tool in a direction transverse to the direction of the primary movement of the tool.
  • the stretching tool comprises an array of at least six neighbouring separable tips which simultaneously engage the sheet. As the tool touches the sheet, at each point of contact it chills a blob of the hot plastics material so strengthening the blob and enabling it to resist puncture by the tool even if the tool is needle sharp.
  • the strengthened chilled blobs also enable the sheet to stretch in response to pressure exerted on the blobs by the tool.
  • this invention also provides a stretch-formed hollow plastics container comprising a base and side wall characterised in that the perimeter of the base is marked by blobs of less stretched plastics material. Usually the blobs are virtually unstretched and unthinned.
  • thermoplastic material examples include:
  • aliphatic (preferably crystalline) polyolefins including poly-4-methyl pentene-1, polybutenes, low, medium, and high density polyethylenes or copolymers of ethylene with vinyl alcohol, vinyl acetate, acrylic or methacrylic acids or their methyl, propyl, ethyl or butyl esters or homopolymers of propylene or copolymers of propylene with up to 30% (by weight of the copolymer) of ethylene and preferably the ethylene and propylene polymers should have a melt flow index of between 0.1 to 8 g/10 minutes as measured according to British Standard 2782 Part 1/105C of 1970 except that in the case of polymers containing a major amount by weight of propylene, a temperature of 230 C is used instead of 190 C;
  • thermoplastic rubbers including ethylene propylene rubbers such as those described in an article by L. M. Glanville in “Chemistry and Industry” 16 Mar. 1974 pages 255 to 257 (the contents of which are herein incorporated by reference) especially when diene modified, using dienes such as 1,4-hexadiene, dicyclopentadiene or methylene or ethylidiene norbornenes and in particular blends of such rubbers with polypropylenes;
  • polyesters such as the condensates of ethylene glycol or tetramethylene glycol or 1,1-(dihydroxymethyl) cyclohexane with terephthalic acid or mixtures of terephthalic acid and isphthalic acid;
  • inorganic glasses including soda or borosilicate glass
  • edges can be used to define for example a slanting or vertical side wall comprising three or more contiguous longitudinal flat or slightly concave panels wherein the boundary between each pair of contiguous panels extends from a blob of less stretched material located on the perimeter of the base of the hollow article.
  • the boundary is often a slight ridge and if unpigmented plastics material is used it can show improved translucency.
  • the edges comprise sharp knife edges, the increase in area of contact between the sheet and stretching tool has little effect on the freedom of the sheet to stretch.
  • Separation of the knife edges also stretches the material of the side walls transversely to the stretch imparted by the initial stretching of the sheet. Accordingly when the sheet comprises a crystalline plastics material at a temperature below (preferably 15 degrees celsius or more below) its crystalline melting point, the initial stretching imparts a longitudinal orientation to the material of the side wall and the separation of the tips and edges imparts a transverse orientation to the material of the base and side wall with the result that the side wall becomes biaxially orientated and hence its hoop strength is improved.
  • the temperature of the sheet is not critical, provided it is hotter than a temperature 75 degrees celsius below the melting point of the thermoplastic.
  • the upper limit is determined only by decomposition or combustion of the thermoplastic.
  • FIG. 1 is a perspective view of a stretch-formed cup
  • FIG. 2 is a partial section on a larger scale on the line 2--2 of FIG. 1;
  • FIG. 3 is a partial section on a larger scale on the line 3--3 of FIG. 1;
  • FIG. 4 is a sectional elevation of apparatus for making the cup shown in FIG. 1;
  • FIG. 5 is an underneath plan in the direction of the arrow 5 in FIG. 1;
  • FIGS. 6 to 9 are views similar to FIG. 4 showing successive stages in the formation of the cup
  • FIG. 10 is a plan view of an arrangement whereby a number of interpenetrating tools cooperate to simultaneously produce a multiplicity of cups;
  • FIG. 11 is a cross-section through FIG. 10 in the direction of arrows 11--11;
  • FIG. 12 is a sectional view showing a modified form of tooling incorporating a mold
  • FIG. 13 is another sectional view of modified tooling employing molding means for recessing a central area of the resultant cup bottom;
  • FIGS. 14 & 15 are schematic views which show a tool suitable for forming a necked-in jar shaped container
  • FIG. 16 is a sectional view of still another modified form of tooling wherein the plunger carrying the blade alignment head is provided with a cam cooperable with cam surfaces on the blades to effect accurate final expansion of the blades;
  • FIG. 17 is a sectional view through double acting tooling for simultaneously forming on opposite sides of the sheet cups which have diameters such that the cups overlap one another in the manner shown in FIG. 10;
  • FIG. 18 is a sectional view through double acting tooling wherein cups having recessed bottoms and stacking rims may be automatically formed on opposite sides of the sheet;
  • FIG. 19 is a schematic side elevational view showing the manner in which tooling may progress toward an intermediate sheet and then in overlapped relation to form cups on opposite sides of the sheet generally using the tooling of FIGS. 17 and 18;
  • FIG. 20 is a transverse vertical sectional view taken generally along the line 26--26 of FIG. 20, and shows the relationship of adjacent tooling arranged in transverse alignment;
  • FIG. 21 is a sectional view through a sheet showing the manner in which it is progressively formed using the tooling of FIG. 17 or 18;
  • FIG. 22 is a perspective view of a sheet which is provided with a series of cusps on opposite sides of the sheet and with the cusps being in alternating relation up and down both longitudinally and transversely on the sheet.
  • FIG. 23 is a diagonal sectional view taken generally along the line 29--29 of FIG. 20;
  • FIG. 24 is a sectional view taken longitudinally of the sheet generally in the direction of the arrows A in FIG. 20, and shows the sheet being held intermediate respective cusps;
  • FIG. 25 is a perspective view similar to FIG. 22 and shows the holding means of FIG. 24;
  • FIGS. 26-29 are schematic views showing the manner in which cups are progressively formed with the cups projecting to opposite sides of the sheet and in alternating up and down relation wherein the cups have their centers progressively moved apart as the cups increase in diameter and depth;
  • FIG. 30 is a sectional view showing tooling for forming a container having a screw threaded neck and of oval cross section;
  • FIG. 31 is a transverse sectional view through the tooling per se taken generally along the line 39--39 of FIG. 30, and shows the elliptical blade layout of the tooling.
  • FIGS. 32-35 are sectional views of tooling for air assisted forming of containers from sheet with a high degree of uniform circumferential orientation
  • FIGS. 36-39 are sectional views of tooling for forming containers having necked-in upper portions and show the manner in which such containers are progressively formed from a sheet;
  • FIG. 40 is a sectional view showing the final container as it is blanked from the sheet
  • FIG. 41 shows a sheet clamped within a clamp having a circular opening and with the sheet having rings thereon;
  • FIG. 42 is a generally sectional view through the assembly of FIG. 41 in its partially stretched condition
  • FIG. 43 is an enlarged sectional view showing the manner in which the draw tooling is expanded so as radially to stretch and orient the plastic sheet material into a generally cup-shaped configuration;
  • FIGS. 44a, 44b and 44c are schematic sectional views showing the manner in which clamped sheet material may be progressively drawn without expansion of the tool and showing specifically how the sheet material thins out more at the base of the resultant cusp than in the clamped area.
  • FIGS. 45a, 45b & 45c are schematic sectional views similar to FIGS. 44a-c, and show prior art arrangements;
  • FIGS. 46a, 46b and 46c are also schematic sectional views, and show the manner in which a sheet may be progressively axially stretched and circumferentially stretched to form a cylindrical on tapered body;
  • FIGS. 47a, 47b and 47c are schematic views showing the timing of tooling with respect to drawing and radial stretching
  • FIGS. 48a, 48b and 48c show containers with walls thickened in different portions in accordance with the timing of the expansion of the tooling in FIGS. 47a, 47b and 47c, respectively;
  • FIG. 49 is a sectional view on an enlarged scale through the cup formed in accordance with FIGS. 47b and 48b;
  • FIGS. 50a, 50b and 50c are schematic views correlating radial orientation with drawn wall thickness and burst strength
  • FIG. 51 is a sectional view through a container wherein there is illustrated the relationship of diameter and thickness of the container wall;
  • FIG. 1 shows a cup 105 mm in diameter at the open end and 65 mm deep, which has been stretch-formed from a sheet of crystalline polypropylene 0.6 mm in thickness.
  • the cup is generally frusto-conical in shape, having a substantially circular base 20 and an outwardly sloping side wall 21.
  • Twenty four short thin blobs 22 of virtually unstretched polypropylene are spaced uniformly around the perimeter of the base 20. These blobs 22, which are exaggerated in the drawings for greater clarity, are 1.5 mm wide, extend 5 mm radially inwards from the perimeter, and stand 1 mm proud of the adjacent surface of the base 20.
  • the blobs 22 are spaced apart by doubly radiussed scallops 23 consisting of orthogonally radiussed curves 24 and 25 shown in FIGS. 2 and 3.
  • Each blob 22 is integral with a band 27 of polypropylene thicker than the adjacent wall portions 26.
  • the bands like the blobs 22, are composed of virtually unstretched plastic.
  • the wall portions 26 are slightly concave, and merge into the scallops 23.
  • the apparatus shown in FIG. 4 comprises a primary plunger 30 sliding in a cylindrical housing 32, which is open at the other end.
  • the plunger 30 supports a number of flat blades 33 pivoted to a slotted flange 31, on the plunger 30 at uniform intervals around the axis, each blade being coplanar with the axis.
  • the outer edge 34 of each blade terminates at the end nearest to the closed end of the housing 32 in a heel 35 and at the other end in a tip 36.
  • the heels 35 rest against the internal surface of the housing 32, which surface slopes inwardly over its length as shown at 37.
  • a secondary plunger 38 slides longitudinally within the plunger 30 to extend therefrom at both ends.
  • Fixed to the end of the plunger 38 projecting from the plunger 30 within the housing 32 is a terminal flat circular plate 40 which has radial slots around its periphery to receive the blades 33.
  • the plunger 38 has a knob 41 fixed to it, with a compression spring 42 retained between the inside of the knob 41 and the adjacent end of the plunger 30.
  • the open end of housing 32 is used to clamp against a lower clamping ring 39 having the same internal diameter as the open end of the housing 32. Clamping force is applied by a partially compressed spring 43.
  • the heels 35 were pressed inwardly by the sloping portion 37 of the internal surface of the housing 32.
  • the blades 33 rotated about their pivots, moving the tips 36 outwardly away from one another, as shown in FIG. 7.
  • the portions 46 of the sheet were stretched, mainly longitudinally as well as laterally according to the position and shape of the sloping surface 37, and the portion 47 inside the array of tips 36 was stretched uniformly in all directions, i.e. biaxially oriented.
  • the plunger 38 was retracted until the sleeve 39 contacted the plunger 30, whereupon the plungers 38 and 40 were retracted together to the position shown in FIG. 4.
  • the housing 32 was then lifted from the sheet allowing the finished product, which was a cup as shown in FIG. 1, to be removed from the apparatus.
  • the cups formed by the apparatus shown in FIG. 4 may be further dilated by blowing while still hot enough to be deformed into a female mold slightly larger than the cup, as shown in FIG. 12.
  • a suitable polypropylene for making cups illustrated in the drawings has a melt flow index of 1.5 g/10 minutes and is a sequential copolymer of propylene with 13% (by weight of the copolymer) of ethylene made by injecting ethylene into the closing stages of an otherwise homopolymerisation of propylene.
  • the sheet polypropylene is heated to a temperature of 160 degrees celsius and the tips and knife-edges of the stretching tools are heated to 100 degrees celsius.
  • the invention also provides a stretching tool comprising outwardly separable tips.
  • the thickened ribs or bands 25 are deliberately formed to perform two functions, first to control the stretching during hot-forming, second to stiffen the cup. It can be shown that the structure of the wall, namely relatively thick ribs connected by thinner webs, curved or flat, gives superior stiffness to weight properties over conventional, uniform thickness container walls.
  • a plain polystyrene cup weighing 14.95 g having a wall thickness varying between 0.5 mm and 0.3 mm was tested and found to have a crush load of 37 kg.
  • Relatively independent control of the forming of the webs and the chilled reinforcing ribs can be achieved by using enough knife blades so that the combined effect of the increased viscosity of the chilled material can draw out material from the parts of the material not in contact with the blades.
  • the portion of the blades in contact with the material define the position and length of the reinforcing ribs.
  • the path of the blades can be designed so as to give a predetermined length of contact between blades and material. This in conjunction with the time of contact and the area of chilling at the blade/material interface control the thickness of the rib. In general it is preferred to produce the thickest possible rib, and the rib to web wall thickness ratio should preferably exceed 1.5 for significant stiffening to occur.
  • the containers produced by the apparatus of FIG. 4 have walls which are often biaxially oriented and hence have improved hoop strength. Where it is intended to further biaxially orient the containers by inflation as shown in FIGS. 14 and 15, the ribs serve as a reservoir of amorphous material permitting elongation in both width and length yet serving to deliver the material in a controlled way.
  • FIG. 12 it will be seen that this view corresponds to FIG. 9 except that the support ring 39 has been modified to be in the form of a female mould 60 which cooperates with the blades 34 in the forming of the container.
  • air be introduced into the container as formed by the blades 34 with the air being under pressure and sufficient further to deform the container to match the internal configuration of the mould 60.
  • an air line 61 is coupled to the housing 32.
  • the plunger 38 carries a suitable sealing ring 62 which forms a seal with the exterior of the plunger 38.
  • the bearing 31 carries a suitable sealing ring 63 which forms a seal with the exterior of the plunger 30.
  • FIG. 13 is also a modification of the moulding apparatus of FIGS. 6-9 and differs therefrom only in that the plate 40 is formed to have an increased thickness and is provided on the underside thereof with a central recess 64.
  • the plate 40 cooperates with a male mould member 65 which is supported for vertical movement by a support 66 to form in the bottom of the resultant container a recessed area 67.
  • FIG. 16 wherein it will be seen that the housing 32 is cylindrical and is free of its cam shaped interior. Instead, the plate 40 has formed on the upper surface thereof a cam ring 68 which is engageable with the inner edges of the blades 33. In addition, the inner edge of each blade 33 is provided with a cam 69 which cooperates with the cam 68 to effect the wedging or camming out of the blades 33 as the plunger 38 and the cam ring 68 move downwardly.
  • FIGS. 10 and 11 there has been illustrated an embodiment wherein containers are simultaneously formed at opposite sides of the sheet wherein the formed containers overlap one another when viewed in plan as shown in FIG. 10.
  • the tooling includes a pair of spaced platens 70, 71 which are gradually moved together as the forming apparatus and sheet move along a straight line path.
  • Each of the platens 70, 71 carries plural tooling which serves to form, on opposite sides of the general plane of the sheet 72, containers 73.
  • the tooling includes cooperating components carried by the two platens 70, 71.
  • Each fixed tooling unit generally identified by the numeral 74, includes a support sleeve 75 carried by the respective platen.
  • a sleeve 76 extends through and is carried by an auxiliary platen 77.
  • the secondary platen 77 is mounted for limited movement relative to its respective primary platen.
  • the secondary platen in turn, carries a mounting head 78 to which there is pivotally mounted by means of pivots 79 a plurality of forming blades 80, which blades are in circumferentially spaced relation.
  • the sleeve 76 carries at its end remote from the platen 71 a blade guide arrangement 81 which maintains the blades 80 in their respective radial planes.
  • a plunger 82 is journalled in the sleeve 76 for axial movement and is resiliently axially mounted within the support sleeve 75 by means of a spring 83.
  • the upper end of the plunger 82 carries a head 84 for movement therewith and relative to the secondary platen 77 and the sleeve 76.
  • the head 84 is of a slotted arrangement and has guided therein the remote ends of the blades 80.
  • Each blade 80 is provided with a diagonal slot 85 which receives a pin 86 carried by the head 84 wherein relative axial movement of the head 84 relative to the blades 80 will result in the blades 80 being radially outwardly expanded.
  • each tooling set includes a guide sleeve 87 associated with the primary platen 70.
  • a male mould member 89 is slidably mounted within the guide sleeve 87 for cooperation with a recess 90 in the end of the head 84 to form in the respective container a recessed bottom area 91.
  • Each male mould member 89 is urged to its operative position by a spring 92 which is compressed between the primary platen 70 and the mould member 89 and the movement of the mould member 89 through the guide sleeve 87 is limited by means of a headed retaining pin 93 which is slidably mounted in the primary platen 70.
  • the secondary platens 77, 88 carry opposed tubular stop members 94 which limit the movement of the secondary platens 77, 88 together and thus the relative movement of the sets of blades 80 with respect to the general plane of the sheet 72 which is to be formed. It will also be seen that the tubular stop members 94 carry compression springs 95 which bear against the primary platens 70, 71 and normally retain the plungers 82 and the associated heads 84 in retacted relation relative to the blades 80.
  • the plates 70, 71, 77 and 88 are preferably in the form of bars which form portions of endless conveyors with the platens 70, 71 being gradually urged together by way of cams and cam tracks (not shown) so that there is progressive forming of the sheet 72.
  • each container 73 has a reduced diameter neck portion 96 and an outwardly flared flange 97 with there being between the flanges 97 a small scrap part 98.
  • the scrap part 98 is removed leaving the flanged containers 73. It is to be understood that because of the particular relationship of the containers 73 with respect to the sheet 72, it is generally shown in FIG. 10, even the scrap portion 98 is thinned out by stretching so that the scrap may be held to a minimum and on the order of 8% to 15% by weight.
  • FIGS. 6-9, and 12-16 and 32-39 containers are formed to only one side of the sheet material, it will be readily apparent that utilizing light tooling, containers may be simultaneously formed to both sides of the sheet of the type shown in FIGS. 10, 11 and 18, but in non-overlapping relation.
  • FIG. 18 there is illustrated apparatus of the general type shown in FIG. 17 which includes a plurality of remote platens 99 which are parts of two endless conveyors and wherein the platens 99 are in the form of transverse bars which, when they become portions of opposed runs of the conveyor, move together.
  • Each set of tooling includes parts carried by each of the platens 99.
  • Each platen 99 carries a guide sleeve 100 which has slidably mounted therein a guide pin 101 carried by an associated secondary platen 102.
  • Each secondary platen 102 also carries a guide sleeve 103 carrying the respective pin 101 and the guide sleeves 100, 103 are abutable to limit movement of the platens 99, 102 together.
  • the platens 99 and the secondary platens 102 may either be separately mounted for relative movement by means of cams and cam tracks (not shown), or only the platens 99 may be mounted for movement together by means of cam followers and cam tracks. In the latter event, the platens 102 would be resiliently urged away from the platens by springs 104.
  • Each tooling set includes a tubular housing member 105 carried by the platen 99 and is cooperable with tooling carried by the other platen 99.
  • the housing 105 may carry a female mould 106 and in cooperation with that mould provides a step 107 which permits the neck portion of the resultant container to be of a larger diameter than the adjacent portion of the body so as to permit nesting of the containers without wedging.
  • the secondary platen 102 remote from the first mentioned platen 99 carries a sleeve 108 which at its inner end carries a head 109.
  • the head 109 has pivotally mounted thereon by way of pivot pins 110 a plurality of circumferentially spaced blades 111 which are cooperable with the mould 106 to shape a sheet therein to define a container 112.
  • the head 109 carries a forming ring 113 which, in association with the inner part of the housing 105, forms the stepped neck portion of the container 112 together with a flange 114 which lies in the original plane of the sheet.
  • a plunger 115 is slidably mounted within the sleeve 108 and is carried by the remote platen 99.
  • the plunger 115 extends through the head 109 and terminates in a head 116.
  • the head 116 carries a cam 177 which is engageable with cam surfaces 118 on the inner surfaces of the blades 111 to expand the blades to the mould configuration after the sheet has been first drawn into the mould.
  • the container 112 is provided with a recessed bottom 119 which is formed by a cooperating portion of the head 116 and a male mould member 120 which is carried by a rod 121 journalled both in the mould 106 and the associated platen 99.
  • the blades 111 will first serve to form projections on opposite sides of the sheet material and after these projections have been axially completed, they are radially expanded by the blades 111.
  • FIGS. 19, 20 and 21 With respect to the mechanisms of FIGS. 17 and 18, reference is now made to the schematic showings of FIGS. 19, 20 and 21. It will be seen that, with general reference to FIG. 17 and specifically referring to FIG. 19, as the primary plates 70, 71 and the secondary platens 77, 88 move together, the tooling first engages the opposite surfaces of the sheet material in staggered relation, and then progressively effect the drawing thereof into generally cup-shaped configurations in the manner shown in FIG. 21. A typical cup-shaped configuration is identified by the numeral 122 in FIG. 21, the resultant cup-shaped configurations 122 being the result of cuspation. Thereafter, as is clearly shown at the left of FIG. 19, the tooling is dilated radially to stretch and orient the plastic sheet material to form the containers 73 which are in staggered relation on opposite sides of the sheet 72.
  • FIGS. 19 and 20 The inter-nesting relationship of the tooling is clearly shown in FIGS. 19 and 20 and it is to be understood that because the tooling is acting simultaneously on opposite sides of the sheet material 72 and each tooling at one side of the sheet is surrounded by four other tools, there is no need to clamp the sheet and, furthermore, the sheet material intermediate the tooling is also stretched and drawn so that the waste material which exists between adjacent containers 73 is not only small in area, but due to its reduction in thickness, is further reduced.
  • an injection moulded or extruded preform is inflated at the orientation temperature.
  • the screw neck whereby the preform is held during inflation is not itself inflated, and is therefore not oriented at all.
  • FIGS. 22 to 29 One method for achieving this according to our invention is illustrated in FIGS. 22 to 29.
  • a sheet has been drawn in opposite directions to opposite sides thereof to provide groups of cup-like preforms 123 which are arranged in a square array alternately opposed so that each upwardly directed preform 123 is surrounded by four downwardly directed preforms with the entire group comprising an unperforated sheet and the preforms arranged in the sheet in a standing wave pattern as is best shown in FIG. 23.
  • the number of preforms in a single array is not critical, but it has been found useful to employ sheets containing large number of preforms, for example 100 preforms arranged in 10 ⁇ 10 rows. It is also to be noted that the cavities of the preforms 123 are reversed and the walls of the cavities have been formed under tension and whose tensions are confluent with opposite neighbouring cavities except at saddle points 124 (FIG. 24) which may be clamped using clamp rods 125.
  • the preforms 123 may initially be shallowly drawn and while disposed in adjacent relation the spacing between centers of the preforms may be varied by moving adjacent preforms in both longitudinal and transverse directions as indicated by the arrows 126 and 127, respectively.
  • preforms 123 may be stretched and enlarged by both moving the centers apart longitudinally and transversely and by increasing the depth of the draw so as to define deeper and more widely spaced preforms 128 which, of course, have thinner walls.
  • the sheet having formed therein the preforms 128 may then be transferred to another set of tooling shown in FIG. 27 and the spacing between this next set of tooling is then increased both longitudinally and transversely and the depth of the preforms may be increased to define a new set of preforms 129 as shown to the right in FIG. 27.
  • the preforms 129 are now ready for dilation and radial stretching and orientation.
  • the preforms 129 are now presented to dilating tooling in FIG. 28 and each preform 129 is drawn into a generally cylindrical configuration to define preforms 130.
  • These preforms 130 preferably have a depth of the order of twice the desired cup-shaped member and, as is shown in FIG. 29, the sheet may be divided by removing the central portion thereof into a plurality of shallower preforms or cup-like containers 131 as shown in FIG. 29.
  • the mechanisms for changing the center-to-center dimensions of the preforms are not narrowly critical and may include crossed multiple lead feed screws, acting in two axes simultaneously utilized for this purpose.
  • Operation on a sheet of preforms comprises a single press stroke which may exert extensions at rates as high as 100% linear per second, although somewhat slower strain rates enhance the development of crystallinity.
  • a desired preform 137 may either be directly formed from the sheet material 138 in a single operation into the mould 139, or by a plurality of operations as is shown both in FIGS. 26-29.
  • the preform is then placed in a mould 139 of the desired configuration and either before or while within the mould the thick top 140 of the preform is axially stretched by means of a stretch rod 141.
  • the blow moulding preform as shown is finally shaped to generally match the mould configuration as closely as possible utilizing a plurality of blades 142 in the manner previously described, with the blades being progressively opened as axial stretching takes place by way of a control cam 143.
  • the preform 137 is now ready for blow moulding and the thick top 140 provides adequate material for blowing into a screw threaded neck shape.
  • Certain plastics suitable for orientation forming have quite high stretching stresses at orientation temperature.
  • Polyethylene terepthalate for example, has a stretching stress of around 1.5 to 2.0 kilograms per square millimeter at 100 degrees celsius.
  • FIGS. 32 to 35 wherein a form of tool is shown which will enable circumferential orientation of an open mouthed container shape to be attained.
  • the axial orientation ratio is 1.5 to 2.0 and the circumferential orientation ratio is 3 giving and overall stretch of 4.5 to 6.
  • the force of pushing is transmitted from the pin 191, through two pre-compressed coil springs 193 and 194 to flange 196 which pushes blades 190 via pivot points 197.
  • the initial pushing step stretches the sheet until the top surface of housing 198 meets the under side of housing 199 clamping the sheet and sealing it so that air pressure may be applied to the formed sheet via spigots 200 or 201.
  • FIG. 33 shows the material in the pre-stretched clamped position after the first primary movement of clamp 195 is completed.
  • FIG. 34 shows the next sequence in forming wherein air pressure applied through spigot 200 forces the formed material against the closed blade cluster where it is held for a period of time until the temperature of the so formed tube shape 202 lowers to the orientation temperature.
  • the air pressure exerted via spigot 200 is then removed and a second push on flange 195 first pushes the closed blade cluster 190 further into housing 199 until the spring 194 is fully closed, then begins to move pin 191 relative to flange 196, exerting an outward opening pressure on the blades 190.
  • Simultaneously air pressure is introduced via spigot 201 which helps to expand the formed tube 202 against the internal surface of the housing 199.
  • the blades 190 thus only touch the completed forming at the base whereas air pressure completes most of the inflation of the final shape.
  • FIG. 35b wherein ribs 203 connect material tension in the base to tension in the wall via indented saddles 204 so that the ribs 203 stand in relief to form a stable base while the saddle tension forms 204, are maintained between the base and walls.
  • Such a form is well suited to resist the creep and inflation forces on the base and wall which develop when the shape is pressurized.
  • FIGS. 36-40 wherein an apparatus similar to that of FIG. 12 is illustrated and shows the manner in which a necked-in container may be formed on a continuous basis from a continuous sheet or web 145. It will be seen that a mould 146 which is formed in two halves 147, 148 may be carried by two carriages 149, 150, respectively. The mould 146 is of the type to form a necked-in flanged container 151 as is best shown in FIG. 40.
  • a vacuum line 152 which is connected to vent passages 153 in the base of the mould 146.
  • each mould there is a combined housing, clamp and possibly cam member 154 which may correspond to the housing 32 of FIG. 20.
  • the member 154 cooperates with the top of the mould 146 to clamp a selected portion of the web or sheet 145 for forming.
  • a plurality of blades 155 are pivotally carried by a head 156 which, in turn, is carried by a plunger 157. Normally the blades are retracted, as is best shown in FIG. 40. It is to be understood that the blades 155 may be expanded in timed relation to their movement within the mould 146 by means of a cam surface formed on the member 154 in the manner shown in FIG. 20, or by means of a cam, such as the cam 68, carried by a separate plunger. The manner in which the blades 155 are expanded and retracted is immaterial.
  • each pair of carriages will carry a plurality of moulds 146 which are transversely spaced. It is also to be understood that there will be a progressive movement of the housing member 154 and the blades 155 first toward the sheet 145 and then into the mould 146 so that the forming of the containers 151 will be a continuous, progressive operation.
  • FIGS. 36-40 the containers have been illustrated as being formed to one side only of the sheet 145, they may be formed simultaneously to opposite sides of the sheet in the general manner hereinabove disclosed.
  • the sheet 145 has been clamped against the upper surface of the mould 146 by the member 154 and the blades 155 have moved downwardly and are initially drawing the clamped portion of the sheet into the mould, producing an axial stretching of the sheet.
  • vent passages 153 have been illustrated only as being formed in the mould bottom, similar vent passages may also be formed in the mould cylindrical wall.
  • the mounting of the carriages 149, 150 is such that the carriages move independently of one another and as the front carriage 150 moves around an arc in a clockwise direction, it moves away from the rear carriage 149 thereby separating the mould halves 147, 146.
  • the formed container 151 while still being a part of the sheet 145, may now be removed from the open mould by moving the sheet 145 upwardly and to the right in a counterclockwise direction with a similar movement having been imparted to the blades 155.
  • removal of the moulded container 151 is automatic.
  • the individual container 151 is blanked from the sheet 145 and that a closure receiving flange 158 is automatically formed on the container 151 for receiving a suitable closure, for example, secured in place by a conventional seaming operation.
  • FIGS. 41 and 42 It is a mathematically provable fact that when a clamped elastic membrane is drawn down by a free stretch tool into a free tension shape, then the wall thickness is reduced progressively toward the direction of draw. This is illustrated in FIGS. 41 and 42, wherein a sheet of thermoplastic material is held by clamps 160. It is observed during draw without expansion, that a series of circles 161 drawn on the material do not change in apparent size or thickness if viewed from above (FIG. 41).
  • the wall thickness 162 When viewed from the side (FIG. 42), the wall thickness 162 is reduced down the "cusp" shaped surface 163 in inverse proportion to the extended width of the bands 164. No extension of any part of the membrane occurs radially.
  • thermoplastic materials have elasticity to a greater or lesser degree in the melt state. If draw is completed while all of the membrane remains in the melt, thinning out of the lower wall will thus occur as illustrated.
  • Vertical crush strength is often used as the main failure criterion for non-pressure container performance in practice, due to loads imposed for filled and stacked containers when transported.
  • FIGS. 42a, 42b and 42c This is illustrated in FIGS. 42a, 42b and 42c, wherein stretch is shown being initiated and proceeds slowly.
  • the thinner stretched part 166 near to the tips of the tool 165 cools more quickly than the thicker material 167. This thin cooler area becomes stronger and tends to transfer stretch back towards the hotter clamped area. As primary draw is completed the lower wall area 168 is frozen, the upper wall area 169 is warmer and less stiff, hence is stretched out of this area preferentially.
  • U.S. Pat. No. 3,901,640 and U.S. Pat. No. 3,975,493 (1973) teach use of an expanding tool with many blades, which progressively contact the sheet. Striation or marking of the cup is prevented by means of a rubber sleeve fitted over the blades.
  • This tool suffers from a degree of sensitivity to temperature as discussed above, but reduces this somewhat by encouraging friction between the web and the rubber sheet, as a means to controlling thinning down of the lower wall of the container during insertion and expansion of the tool.
  • Expansion occurs after insertion has been completed to at least three quarters of the maximum depth of the final parison.
  • This patent does not therefore teach forming of longitudinal thicker ribs by line contact with blades separated by areas of free draw.
  • FIGS. 46a, 46b and 46c a free stretch tool 165 is shown (FIG. 46a) with contact edges initially closed, and beginning to stretch the sheet. As draw proceeds the edges are expanded outwards (FIG. 46b) in a controlled relationship to draw. On completion of expansion the draw (FIG. 46c) the edges define the final shape of the container 176. No female mould is required to complete the shape of the forming.
  • Expanding tools which contact the melt over a substantial part of the area during draw (more than 20% of the area), work either by preferential chilling, by friction or by a combination of these two.
  • Such tools are almost always too severe on draw down of the melt to be opened during the primary stroke, as this would result in a cup with lower wall too thick. Also such tools are subject to uncontrolled variability in operation due to temperature variations and/or variations in the coefficient of friction between the tool and the web. Consequently product quality is inconsistent.
  • Expanding tools which contact the melt at points or tips, only can be inserted slowly, if stretch control is to occur.
  • FIGS. 47a, 47b and 47c and corresponding FIGS. 48a, 48b and 48c shows a bladed expanding tool 165 which has about 15 blades, each 1 mm thick for a cup diameter of around three inches.
  • FIGS. 47a, 47b and 47c Three relationships of tool expansion to primary draw are shown.
  • An early expansion (FIG. 47c) gives loci of blade tips 177 as shown. This causes a cup to be formed with thin upper wall 178 and thick lower wall 179.
  • a middle expansion tool (FIG. 47b) forms a cup with thickening in the centre wall, as shown in FIG. 48b.
  • a late expansion tool forms a cup with a thick upper wall and a thin lower wall (FIG. 48c).
  • FIG. 49 shows a cup 180 with thin upper wall 181, thick middle region 182 for holding the cup and thin lower wall 183. This provides a thick, reinforced region where the cup has to be gripped, without having wasted material elsewhere.
  • FIGS. 50a, 50b and 50c shows how, using a simple tool, hoop orientation would increase progressively down the wall (FIGS. 50a) to the base.
  • the maximum tensile strength also increases in proportion, hence it is desirable to evenly reduce the wall thickness (FIG. 50b) as the tensile strength of the material increases, so that burst strength is equalized.
  • a further example of where fine control of wall thickness is required, is in forming a bottle parison wherein it is desirable to produce a tube with variations in wall thickness which correspond to the amount of later stretch required when the bottle is blown to its final shape.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
US06/298,917 1978-05-18 1981-09-02 Stretch forming hollow articles Expired - Lifetime US4480979A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US06/298,917 US4480979A (en) 1978-05-18 1981-09-02 Stretch forming hollow articles
AU81441/82A AU8144182A (en) 1981-02-23 1982-02-23 Stretch-forming hollow articles from thermoplastics sheet
BE0/207379A BE892233A (fr) 1981-02-23 1982-02-23 Formage d'articles creux par etirage d'une feuille de matiere plastique
PCT/AU1982/000016 WO1982002850A1 (fr) 1981-02-23 1982-02-23 Formation par allongement d'articles creux a partir d'une feuille thermoplastique
EP82900606A EP0072832A1 (fr) 1981-02-23 1982-02-23 Formation par allongement d'articles creux a partir d'une feuille thermoplastique
ZA821179A ZA821179B (en) 1981-02-23 1982-02-23 Stretch-forming hollow articles from thermoplastics sheet
GR67389A GR76068B (fr) 1981-02-23 1982-02-23
IT8219802A IT1235456B (it) 1981-02-23 1982-02-23 Formazione mediante stiro di articoli cavi da fogli termoplastici.
PT74483A PT74483B (en) 1981-02-23 1982-02-24 Stretch-forming hollow articles from termoplastics sheet
IL65231A IL65231A0 (en) 1981-02-23 1982-03-12 Stretch-forming hollow articles from thermoplastics sheet
KR1019820001168A KR830008818A (ko) 1981-09-02 1982-03-18 열연화판재를 늘림-성형하는 방법 및 장치와 그 제품

Applications Claiming Priority (18)

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AUPD4433 1978-05-18
AUPD443378 1978-05-18
AUPD483378 1978-06-22
AUPD4833 1978-06-22
AUPD826379 1979-04-03
AUPD8263 1979-04-03
AUPD839879 1979-04-17
AUPD8393 1979-04-17
US06/040,312 US4288401A (en) 1978-05-18 1979-05-18 Thermoplastic forming process
AUPE7707 1981-02-23
AUPE770681 1981-02-23
AUPE770781 1981-02-23
AUPE7708 1981-02-23
AUPE770881 1981-02-23
AUPE770581 1981-02-23
AUPE7706 1981-02-23
AUPE7705 1981-02-23
US06/298,917 US4480979A (en) 1978-05-18 1981-09-02 Stretch forming hollow articles

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US (1) US4480979A (fr)
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BE (1) BE892233A (fr)
GR (1) GR76068B (fr)
PT (1) PT74483B (fr)
WO (1) WO1982002850A1 (fr)
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Cited By (19)

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Publication number Priority date Publication date Assignee Title
FR2602712A1 (fr) * 1986-08-18 1988-02-19 Monoplast Sa Procede et dispositif de fabrication de recipients par thermoformage et recipients ainsi obtenus
US4847034A (en) * 1987-05-28 1989-07-11 Shigeru Kogyo Kabushiki Kaisha Vacuum forming method
FR2640545A1 (fr) * 1988-12-16 1990-06-22 Monoplast Procede et dispositif de thermoformage d'objets creux par etirage-compression
US4941814A (en) * 1987-05-28 1990-07-17 Shigeru Kogyo Kabushiki Kaisha Vacuum forming apparatus
US5080853A (en) * 1989-09-07 1992-01-14 Schmalbach-Lubeca Ag Process for deep drawing plastic foils
US5228934A (en) * 1984-05-22 1993-07-20 Highland Supply Corporation Method of forming a flower pot or flower pot cover with controlled pleats
US5231289A (en) * 1991-04-22 1993-07-27 Shimadzu Corporation Thermal photodetector and method of manufacturing the same
US5523046A (en) * 1984-05-22 1996-06-04 The Family Trust U/T/A Method of using a female tool with movable plates to form a sheet of material into a flower pot or flower pot cover having outward fins
US5573789A (en) * 1984-05-22 1996-11-12 Southpac Trust International, Inc. Apparatus having blades and plates for forming sheet material into a flower pot cover having outward fins
WO1996039892A1 (fr) * 1995-06-07 1996-12-19 Samsonite Corporation Bagage forme par pression differentielle, a cadre integre moule
US5637330A (en) * 1995-06-07 1997-06-10 Samsonite Corporation Apparatus for differential pressure forming shells for hard sided luggage containers
US5755311A (en) * 1995-06-07 1998-05-26 Samsonite Corporation Differential pressure formed luggage with molded integrated frame
US5798079A (en) * 1996-08-20 1998-08-25 Fort James Corporation Method and apparatus for forming drink-thru cup lids
US5868309A (en) * 1996-07-26 1999-02-09 Fort James Corporation Carton having buckle-controlled brim curl and method and blank for forming the same
EP1543940A1 (fr) * 2003-12-16 2005-06-22 Marbach Werkzeugbau GmbH Moule à thermoformage
US20070182065A1 (en) * 2006-02-07 2007-08-09 Adams Thomas R Method and mold for making non-metallic fiber reinforced parts
WO2008040821A2 (fr) * 2007-02-28 2008-04-10 Basf Se Corps creux en polystyrene obtenu par soufflage-injection
US20100080874A1 (en) * 2007-02-28 2010-04-01 Basf Se Hollow polystyrene body obtained by injection stretch blow moulding
US20110001263A1 (en) * 2009-07-01 2011-01-06 Christophe Bonnier Piston for Positioning a Food Pot Decoration in a Mold, Associated Device and Associated Method

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FR1238800A (fr) * 1959-07-06 1960-08-19 Hoechst Ag Procédé d'étirage ou d'emboutissage profond et guidé pour la fabrication de corps creux en matières synthétiques thermoplastiques
GB860810A (en) * 1957-01-22 1961-02-08 Ici Australia Ltd Method and apparatus for the production of hollow articles
US2985915A (en) * 1958-12-12 1961-05-30 Hedwin Corp Thermoforming process for thermoplastic sheeting
US3975493A (en) * 1973-12-03 1976-08-17 The Dow Chemical Company Method for forming hollow articles from thermoplastic sheeting or film using an expandable plug

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GB860810A (en) * 1957-01-22 1961-02-08 Ici Australia Ltd Method and apparatus for the production of hollow articles
FR1214895A (fr) * 1958-08-26 1960-04-12 Comptoir Des Prod Chim Ind Procédé et dispositif pour la fabrication de corps creux en matière plastique
US2985915A (en) * 1958-12-12 1961-05-30 Hedwin Corp Thermoforming process for thermoplastic sheeting
FR1238800A (fr) * 1959-07-06 1960-08-19 Hoechst Ag Procédé d'étirage ou d'emboutissage profond et guidé pour la fabrication de corps creux en matières synthétiques thermoplastiques
US3975493A (en) * 1973-12-03 1976-08-17 The Dow Chemical Company Method for forming hollow articles from thermoplastic sheeting or film using an expandable plug

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5228934A (en) * 1984-05-22 1993-07-20 Highland Supply Corporation Method of forming a flower pot or flower pot cover with controlled pleats
US5626701A (en) * 1984-05-22 1997-05-06 Weder; Donald E. Method using blades and fins to form sheet material into a flower pot cover having inward fins
US5573789A (en) * 1984-05-22 1996-11-12 Southpac Trust International, Inc. Apparatus having blades and plates for forming sheet material into a flower pot cover having outward fins
US5523046A (en) * 1984-05-22 1996-06-04 The Family Trust U/T/A Method of using a female tool with movable plates to form a sheet of material into a flower pot or flower pot cover having outward fins
EP0259214A1 (fr) * 1986-08-18 1988-03-09 Monoplast S.A. Dispositif de fabrication de récipients à fond surélevé par thermoformage
FR2602712A1 (fr) * 1986-08-18 1988-02-19 Monoplast Sa Procede et dispositif de fabrication de recipients par thermoformage et recipients ainsi obtenus
US4941814A (en) * 1987-05-28 1990-07-17 Shigeru Kogyo Kabushiki Kaisha Vacuum forming apparatus
US4847034A (en) * 1987-05-28 1989-07-11 Shigeru Kogyo Kabushiki Kaisha Vacuum forming method
FR2640545A1 (fr) * 1988-12-16 1990-06-22 Monoplast Procede et dispositif de thermoformage d'objets creux par etirage-compression
US5080853A (en) * 1989-09-07 1992-01-14 Schmalbach-Lubeca Ag Process for deep drawing plastic foils
US5231289A (en) * 1991-04-22 1993-07-27 Shimadzu Corporation Thermal photodetector and method of manufacturing the same
US5894007A (en) * 1995-06-07 1999-04-13 Samsonite Corporation Differential pressure formed luggage with molded integrated frame
WO1996039892A1 (fr) * 1995-06-07 1996-12-19 Samsonite Corporation Bagage forme par pression differentielle, a cadre integre moule
US5637330A (en) * 1995-06-07 1997-06-10 Samsonite Corporation Apparatus for differential pressure forming shells for hard sided luggage containers
EP0781104A1 (fr) * 1995-06-07 1997-07-02 Samsonite Corporation Bagage forme par pression differentielle, a cadre integre moule
EP0781104A4 (fr) * 1995-06-07 1998-05-20 Samsonite Corp Bagage forme par pression differentielle, a cadre integre moule
US5755311A (en) * 1995-06-07 1998-05-26 Samsonite Corporation Differential pressure formed luggage with molded integrated frame
US5868309A (en) * 1996-07-26 1999-02-09 Fort James Corporation Carton having buckle-controlled brim curl and method and blank for forming the same
US5798079A (en) * 1996-08-20 1998-08-25 Fort James Corporation Method and apparatus for forming drink-thru cup lids
US5996837A (en) * 1996-08-20 1999-12-07 Fort James Corporation Method and apparatus for forming drink-thru cup lids
EP1543940A1 (fr) * 2003-12-16 2005-06-22 Marbach Werkzeugbau GmbH Moule à thermoformage
US20050142239A1 (en) * 2003-12-16 2005-06-30 Marbach Werkzeugbau Gmbh Thermoforming tool
US20070182065A1 (en) * 2006-02-07 2007-08-09 Adams Thomas R Method and mold for making non-metallic fiber reinforced parts
US7704067B2 (en) * 2006-02-07 2010-04-27 Tiodize Company, Inc. Method and mold for making non-metallic fiber reinforced parts
US20100080874A1 (en) * 2007-02-28 2010-04-01 Basf Se Hollow polystyrene body obtained by injection stretch blow moulding
WO2008040821A3 (fr) * 2007-02-28 2008-09-18 Basf Se Corps creux en polystyrene obtenu par soufflage-injection
WO2008040821A2 (fr) * 2007-02-28 2008-04-10 Basf Se Corps creux en polystyrene obtenu par soufflage-injection
CN101616844B (zh) * 2007-02-28 2011-04-20 巴斯夫欧洲公司 通过注拉吹塑成型获得的聚苯乙烯中空制品
US8545953B2 (en) 2007-02-28 2013-10-01 Styrolution GmbH Hollow polystyrene body obtained by injection stretch blow moulding
KR101485205B1 (ko) 2007-02-28 2015-01-27 바스프 에스이 사출 연신 취입 성형에 의해 얻어진 폴리스티렌 중공체
US20110001263A1 (en) * 2009-07-01 2011-01-06 Christophe Bonnier Piston for Positioning a Food Pot Decoration in a Mold, Associated Device and Associated Method
US8641405B2 (en) * 2009-07-01 2014-02-04 A R C I L Piston for positioning a food pot decoration in a mold and associated device

Also Published As

Publication number Publication date
ZA821179B (en) 1983-04-27
PT74483B (en) 1983-09-26
WO1982002850A1 (fr) 1982-09-02
PT74483A (en) 1982-03-01
BE892233A (fr) 1982-06-16
GR76068B (fr) 1984-08-03
EP0072832A1 (fr) 1983-03-02

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